Praise For The 80m Band and NVIS.

Started by gil, May 09, 2017, 07:16:53 pm

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August 23, 2017, 10:04:14 am #15 Last Edit: August 23, 2017, 10:09:16 am by cockpitbob
Here's a nice write-up on short 80M verticals.  Lots of good construction pictures and background info.

I have a home-brew 6M - 40M no-tuner vertical but need something for 80M with the sun going to sleep for the next 6 years.

Yeah, I should take pics and write-up my vertical.  It's pretty simple.  5' of aluminum tent poles(brass screws between sections), then a home brew coil on PVC pipe, then an MFJ 6' telescoping whip.  I cut grooves in the pipe so I can use a clip lead to adjust the number of turns.  To change bands I move the clip lead to the desired tap on the coil then adjust the length of the 2 radials I have on SOTAbeams wire winders.  I wind or unwind wire to set the radial length.  I have marks on the wires for typical lengths.  Having wire bunched up on the winder seems to be the same as not having it there at all.  It works quite nicely, though I should carry an antenna analyzer to make sure the tune is good.

For me, winding coils is a PITA.  So, here's a thought.  Use a $17 MFJ 30meter or 40meter hamstick as the base coil and attach whatever length of wire to the top to get it tuned for 75M or 80M.  If you can't get a string over a branch for pulling up the wire, a telescoping Jackite pole will work.  For mobile opps I use my 20M hamstick on 17M and 15M just by using shorter whips.  It will work the other direction by using a longer whip for lower bands.  MFJ makes 75M and 80M ham sticks, but they are too short (about 9' overall) to really work on such long wavelength bands.


It would be good if you can get around to a write up and photos of your vertical. I should of course do the same for mine, but they are not made nicely and may not look great in photos.